The background description provided here is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
Vehicle electronic control systems, such as engine control systems and transmission control systems, use electrical and electro-mechanical devices (e.g., circuits) to monitor operating conditions and to adjust operation. The vehicle control systems may include diagnostic systems that determine whether the devices (e.g., devices generating input signals and output devices) are functioning as designed. Demands on the diagnostic systems have increased as the vehicle control systems have become more complex. A requirement of vehicle diagnostic systems may be quick and accurate detection faults, including both continuous and intermittent faults, in order to maintain reliable operation of the control system.
Functional performance requirements of a vehicle control system or a particular subsystem and its components may vary. For example, the diagnostic system may be required to detect and respond to an electrical fault of a first device or first input signal in less than 50 milliseconds to maintain and stabilize operation of the control system. Other input signals or output devices may allow diagnosis and response over longer or shorter intervals.